This is shocking: Californians’ median household income plunged an incredible 9 percent in four years, from 2006-10. The amount dropped to $54,459 annually from $59,821, adjusted for inflation, according to a U.S. Census Bureau report last week.

The recession that began in December 2007 hit all of America. But median income nationwide dropped 5 percent from 2006-10. So California’s damage was almost twice as bad. Moreover, the national drop in income didn’t begin until 2008. But the California drop began a year earlier.

What happened?

The biggest culprit remains California’s “disproportionate exposure to the construction industry,” which crashed beginning in 2006 and has not recovered, says Esmael Adibi, director of the A. Gary Anderson Center for Economic Research at Chapman University. Now, he said, “The best thing is to do anything to stop blocking the jobs-creation machine.”

Yet one public policy hindering that machine is Assembly Bill 32, the Global Warming Solutions Act of 2006, signed into law with great fanfare by then-Gov. Arnold Schwarzenegger. AB32 mandates that California’s greenhouse gas emissions be reduced by 25 percent by 2020. Regulations to accomplish that, though, could eliminate up to 1 million jobs, according to a 2009 Cal State Sacramento study.

“AB32 and its related components, like the renewable portfolio standard and low-carbon fuel standard, are a major reason California is suffering more than the rest of the nation in terms of unemployment and median income,” Tom Tanton told us; he’s president of T2 & Associates, a technology and energy consulting firm, and a former policy adviser to the California Energy Commission. “Driving energy costs higher and productivity lower, AB32 is the albatross around the neck of California’s economic engine.”

The census report also found that, in 2010, 16.3 percent of Californians earned incomes below the poverty level, a 15-year high and higher than the nation’s 15.1 percent rate.

All of this is further evidence that California’s high-tax, high-regulatory environment is toxic to jobs and business creation. Where are the leaders who will restore fiscal and regulatory sanity?